The present invention relates generally to record disc playing apparatus having the function for correcting rotational irregularities due to record disc eccentricity. More particularly, the invention relates to a record disc playing apparatus which corrects rotational irregularities due to record disc eccentricity and is capable of reproducing and playing a record disc in an excellent manner in a state without irregularities at any portion of the record disc from its outer periphery to its innermost recorded part.
In general, at the time of molding record discs, it is difficult to provide all record discs with central holes that are exactly coincident with the center of rotation, and these central holes all have some kind of offset from the true rotational center, that is, have eccentricities.
When a record disc with such an eccentricity is placed on a turntable rotating at a constant rotational angular velocity and is played by a reproducing stylus caused to trace along the record sound groove, the relative linear velocity between the stylus and the second groove varies as a result of the rotational irregularity caused by the eccentricity, whereby wow is generated in the reproduced signal. The quantity of this wow in the reproduced signal varies in inverse proportion to the distance from the rotational center of the record disc to the portion of the tip of the reproducing stylus.